The present invention relates to an electronic connection unit in the form of a PC card, for connecting to a small smart card such as a Micro Sim card. The invention more particularly relates to a PCMCIA (Personal Computer Memory Card International Association) standard PC card which can be inserted into a host such as a personal computer to make one or more connections between the small smart card and the computer and/or peripherals connected to a front end of the PC card. It is noted that the PCMCIA standards relate to the external dimensions of the connection unit, in order to make it possible to insert a standard PC card into any personal computer which includes an insertion slot or passageway whose dimensions correspond to the PCMCIA standards.
The present PC card or electronic connection unit in the general form of a card, includes a metal shell made in two (possibly merging at one end) parts, with upper and lower parallel plane main walls and with side walls which, between them, form a cavity. A circuit board lies in the cavity and is spaced between the upper and lower walls. The circuit board may carry electronic components and, at its opposite longitudinal ends, PC card connectors and/or spacers. A connector at the PC card rear end can connect to a host connector lying at the rear of the host passageway. If the PC card has a PC card connector at its front end, such front connector may, for example, receive a plug for connection to a telephone line.
For some applications, such as to allow a personal computer user to access a telecommunications network, it has become necessary to be able to associate the PC card with a small smart card. Such small smart card comprises a plastic plate that is usually less than one millimeter thick, that usually has a memory that stores information, and has a group of contact pads for accessing the memory. This principle of authorizing access to a user owning a miniature or small smart card is commonly applied in the field of radiotelephony. A common smart card is a "MICRO SIM" card of standard dimensions.
It has been proposed to associate a small smart card connector with a PCMCIA connection unit, or PC card. However, designs known to date have unacceptably reduced the rigidity and the electronic screening characteristics, or EMI (electromagnetic interference) protection, of the PC card which the metal shell provides.